Automatic caging device fob



Feb. 17, 1942. s. J. ZAND 2,273,309

AUTOMATIC CAGING DEVICE FOR GYROSCOPES Filed Nov. 26, 1938 2 Sheets-Sheet l i d e gJ. 5

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AUTOMATIC GAGING DEVICE FOP. GYROSCC'PES Filed Nov. 26, 1938 2 Sheets-She-et 2 giga 4l [gul STE/233% p BY im MAT'TORNEY lUNITED STATES PATENT OFFICE Avremmo cAGmG DEVICE Fon Graoscorns stephen J. zand, Forest mus, N. Y., assignmto Sperry Gyroseope Company, Inc., Brooklyn, N. Y., a corporation of New York Application November 2s, 193s, serial No.-z4z,54z

(ci. 'i4-5) 9 Claims.

This invention relates to position maintaining or directional gyroscopes and more particularly to such gyroscopic instruments used on moving craft such as airplanes and the like. Since the directional gyroscope has no directive force, it is usual to provide a resetting device therefor, so that the readings of the same may be corrected from time to time.

The purpose of this invention is to provide noveland eillcient' means to cage or lock the gyroscopic element about its horizontal axis so that no precession of the gyro wheel can occur while the element is manually orientated or reset by the operator.

Another purpose of the invention is to provide means by which the gyroscopic element is automatically caged if the air supply to the gyroscope is interrupted, be it manually, by closing a valve in the supply line, or be it accidentally, by failure of the air supply. A further purpose of the invention is to couple the setting knob by which the gyroscope is orientated with the caging device for the gyroscopic element so that it is impossible to orientate the instrument without iirst caging the gyro.

In the accompanying drawings,

Fig. 1 shows a. vertical section through the directional gyroscope.

Fig. 2 shows a plan view of the instrument with .the casing and certain other parts removed.

Fig. 3 is a plan view of the rotor and rotor f bearing ring.

Fig. 4 is azvertical section through part ofthe caging means.

The directional gyroscope is shown. in Fig. 1 as contained in a casing I, which 'may be evacuated by means of an air pump or similar device through pipe 2. The air enters into the casing I through a lter 3. The casing is connected to a base 4 and contains in its upper part the ball bearing 5. The base 4 contains a combined radial and thrust bearing 6, so that the vertical frame 'I can freely rotate on its pivots 8 and 9. By means of two horizontal pivots I and Il, a rotor bearing frame I2 is mounted for oscillation around the horizontal axis in ball bearingsv I3 and I4, which are held in the vertical frame 1. The vertical frame consists of two parts held together byl screws I5 in order to facilitate assembly o f the rotor inside of the frame. Therotor I6 is shown as of the usual air spun type and is` formed in known manner as a wheel 'with pockets Il between two flanges I8 and I9. The rotor I6 is driven by means of an air jet or jets issuing from nozzle or nozzles 20',

.to which air is supplied through passages 2| and 22 connected to the outside atmosphere through the nlter 3. The rotor bearing frame I2, which is shown more in detail in Fig. 3, carries at four points of its outer periphery rollers 23, 24, 25, and 26, each of which can rotate around the shaft of its holding screw. Directly under these rollers is located the caging ring 26', which is carried on four studs 2, 23, 29, and 30,.shown in Fig. 2 and in Fig. 4. These studs have their free ends fastened to the end plates 3l of four metallic bellows or Sylphons each located within a separate air tight enclosure. One of these structures is illustrated in Fig. 4. A stufng box 34 serves the purpose of preventing leakage of air from the enclosure 33 into the interior of the casing i. The pocket 33 is connected by means of a passage 35 to an air duct 3l, while the 4interior of the shown, the channel 36 is connected to an air passage I0 which is connected with the atmospheric air. If the stem 38 by means of the knob 4l is pulled to the left, the air duct 36 is connected to the interior of casing I by means of a passage 42. In this case, the bellows are evacuated and the pressure of the atmospheric air in the pockets 33 will compress the bellows into the position shown in Fig. 4, holding the ring 26' in its lowest position. If now the air supply should fail, the vacuum in bellows 32 and in casin'g I would disappear, thereby allowing the bellows 32 to expand under the inuence of its own resiliency, lifting the ring 26 until this ring makes contact withy the four rollers, 23, 24, 25, and 26, so that the rotor bearing frame I2 is rmly locked.. If during normal operation the knob 4I is pushed to the right, the same effect is produced because the interior of the bellows becomes connected to the outside atmosphere so that due to the absence of any of the scale 45 with respect to a. pointer'which may be located on a mask 46 behind a transparent window 41.

It is evident from the above description that the meshing of the two gears 43 and M simultaneously causes the caglng of the gyroscope, so that precession of the gyro wheel I6 due to turning around the vertical axis is prevented. The automatic caging of the gyro wheel in case of failure of the air pump, or in case of intended interruption of the air supply prevents the gyro wheel from tilting after it comes to rest, so that it is always in properly aligned position whenever the instrument is-started up again. As soon as the air pressure is re-established or as soon as theair pump is active again, the caging ring will automatically be retracted, freeing the gyro wheel as its starts to rotate.

If the instrument were to be driven by direct positive pressure instead of by evacuation, the caging device would operate equally well, and all that would be necessary would be to interchange th passages 36 and 31.

It also is possible to apply the device to any other air driven gyroscopic instrument, as for instance, a vertical gyro, as any one skilled in the art will readily understand.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. v

Having described my invention, what I claim and desire to secure by Letters Patent is:

l. An automatic caglng device for gyroscopes comprising a plurality of metallic bellows and a caging ring supported thereby, a gyroscopic element supported for oscillation around two mutually perpendicular axes and including a rotor, means for operating said rotor by means of a differential pressure, and means for applying said differential pressure to' said bellows to maintain said bellows in a compressed state, whereby upon failure of said pressure said bellows expand t advance said ring to cage said gyroscopic element against oscillation around one of its axes.

2. In a position maintaining air spun gyroscope, a support, a gyroscopic element suspended thereon for oscillation about two mutually normal axes, a rotor for the gyroscopic element. a caging means for locking said element to prevent oscillation about at least one of said axes, a resilient expansible container cooperating with said caging means for normally locking said element, means whereby a pressure differential is supplied for spinning the rotor of the gyroscopic element, and means for connecting said container to said pressure diierential so as to normally hold said cage in the unlocked position as long as the pressure differential is maintained, but to render said cage operative upon failure thereof to lock the gyroscopic element.

3. In an air driven4 directional gyroscope havtial operating pressure to said rotor, a cage for locking the frame about its horizontal axis only, resilient means for holding said cage locked subject to the diierential air pressure for holding it unlocked during operation of the gyroscope, and an air valve connected to said knob adapted, when said knob is in said one position, to relieve the differential pressure affecting said resilient means to thereby cause the frame to be caged at the time said gyroscope is being set.

4. In an air driven directional gyroscope, an outer casing, a vertical ring pivotally mounted therein for orientation about a vertical axis, a rotor bearing frame pivotally mounted within said ring for oscillation about a horizontal axis, means for maintaining a pressure within said casing diil'erent from that of the atmosphere, an automatic caging means for said frame including a spring expanded container normally collapsed by the pressure diierential to keep said caging means inoperativaa gear on said vertical ring, a movably mounted, normally disengaged cooperating gear for turning said ring about its vertical axis, and a valve connected to the latter gear adapted to be moved when said gears are moved into engagement, said valve operating to equalize the pressure in said container and casing,

to effect the locking of the rotor bearing frameA about its horizontal axis by said automatic caging means and by the engagement of said gears permit the resetting of the vertical ring of the gyroscope to any position about its vertical axis.

5. A gyroscopic direction indicator as claimed in claim 4, wherein said automatic caging means is also brought into operation by-failure of the operating air pressure.

6. In a caging device for a gyroscope having three degrees of freedom and having an air spun rotor and -a rotor bearing frame, means for supplying air to the gyroscope at a pressure different from that of the atmosphere for spinning the rotor, a movable lock for engaging the rotor bearing frame to prevent oscillation of the same, and means for automatically bringing said lock into engagement with the rotor bearing frame to lock the same upon failure of the supplied air pressure including a biased expansible container, subject on one side to atmospheric pressure and on the other to the supplied air pressure, so that said lock engages the rotor bearing frame at all times except when the gyroscope and container are aected by the din'erential pressure.

7. In a position indicating instrument, a casing, a gyroscopic element suspended thereinvfor oscillation around a vertical and a horizontal axis, a rotor for the gyroscopic element, resiliently biased caging means normally locking said element to prevent oscillation about one of its axes, means for supplying a pressure differential between the atmosphere' and the inside of the casing `for spinning the rotor of the gyroscopic element, and means responsive to the pressure diilerential for rendering said caging means inoperative.

8. In a. position maintaining gyroscope, a support, a gyroscopic element suspended thereon [or oscillation around two mutually perpendicular axes, a rotor for the gyroscopic element, a caging ring adapted to normally lock said element to prevent oscillation thereof around one of its axes, a plurality of resilient metallic bellows supporti ing said ring, means for supplying a pressure diilerential for'spinning the rotor of the gyroscopic element, and means for utilizing the pressure differential between the inside and outside v of said bellows for changing the length of the bellows so that the caging ring is retracted to unlock said gyroscopic element.

9. In a position maintaining gyroscope, a nor' around one of its axes, a plurality of resilient 10 metallic bellows 4supporting said ring, means for mounting said bellows in separate containers connected to the atmosphere, and means forA connecting the inside of said bellows to the inside of said casing, the normal differential pressure between the atmosphere and the inside of the casing being eiective to change the length of the bellows to unlock the gyroscopic element.

STEPHEN J. ZAND. 

